221 research outputs found

    1H NMR and kinetics studies of the reaction of 4-methyl, 4-bromo and 3-trifluoromethyl benzyltriflones with aromatic nitro-compounds

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    AbstractRate measurements are reported for the reactions in methanol of carbanions derived from benzyltriflones, 2a–c, with 4-nitrobenzofurazan derivatives, 4a and 4b, to give anionic σ-adducts. 1H NMR studies in DMSO-d6 of the reaction of benzyltriflones, 2, and 4-nitrobenzofurazan, 4a, in the presence of triethylamine are consistent with products formed by the elimination of trifluoromethyl sulfinic acid from σ-adducts initially formed by carbanion attack at the 5-position of 4a. Evidence for the high steric requirements of the benzyltriflone anions come from the low value of β; the slope of the linear plot of values of logk5 versus pKa

    Implicative algebras and Heyting algebras can be residuated lattices

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    The commutative residuated lattices were first introduced by M. Ward and R.P. Dilworth as generalization of ideal lattices of rings. Complete studies on residuated lattices were developed by H. Ono, T. Kowalski, P. Jipsen and C. Tsinakis. Also, the concept of lattice implication algebra is due to Y. Xu. And Luitzen Brouwer founded the mathematical philosophy of intuitionism, which believed that a statement could only be demonstrated by direct proof. Arend Heyting, a student of Brouwer’s, formalized this thinking into his namesake algebras. In this paper, we investigate the relationship between implicative algebras, Heyting algebras and residuated lattices. In fact, we show that implicative algebras and Heyting algebras can be described as residuated lattices

    The Effect of Burnout on Organizational Citizenship Behaviour: The Mediating Role of Job Satisfaction

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    The purpose of this study was to investigate the effect of burnout on organizational citizenship behavior (OCB) in a mediating model in which the job satisfaction was contextual state.  Data were obtained from 257 nurses from three university hospitals. While the data involving burnout and job satisfaction were gathered from the nurses, OCB data were obtained from supervisors. The findings of hierarchical regression analysis demonstrated that the only contributor burnout dimension on OCB-O (ODB toward organization) was the reduced personal accomplishment while emotional exhaustion and depersonalization had no effect. Also the findings of mediation analysis showed that job satisfaction is a mediator in the relation between reduced personal accomplishment and OCB-O and it is not a mediating factor in relation between all three burnout dimensions and OCB-I (OCB toward individuals)

    Evaluating the analgesic effect of Cucurbita maxima Duch hydro-alcoholic extract in rats

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    Background and aims: Cucurbita maxima Duch (CMD) is used as sedative for tooth and ear pain, but its analgesic effect has not been research in experimental studies. The aim of this study was to investigate the analgesic effect of hydro-alcoholic extract of CMD was studied using formalin model in rats. Methods: In this experimental study, 60 Rats were randomly divided into 6 equal groups. Control group was injected distilled water and three experimental groups were injected CMD extracts (50, 100 and 200 mg/kg). Group 5 received ibuprofen and group 6 received naloxone with the most effective dose of the extract. Extract or drugs were injected 15 minutes before formalin injection. The responses of animals to pain were recorded for 30 min. after the formalin injection. Responses of first 0-5 min. were considered as acute pain and responses of 15-30 min. as chronic pain. Results: CRM extracts reduced acute pain in doses of 100 and 200 mg/kg (P<0.001). In addition, the extract decreased chronic pain in all used concentrations compared to the control group (P<0.001). Naloxone inhibited analgesic effect of the extract (P<0.05). Conclusion: CRM extracts reduce acute and chronic pains in formalin test through opioid system and it might be used as an analgesic drug

    Characterizing the properties of sustainable semi-flexible pavement produced with polymer modified bitumen

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    Semi-Flexible Pavement (SFP) is a composite type of pavement produced by manufacturing of porous asphalt mixes using open graded aggregate gradation to create 20-35% of voids filled with grout (cement paste, cement mortar, etc.….). The resulting pavement has the flexibility of asphalt pavement and some strength of concrete pavement. The current study focused on investigation of using widely available (in Iraq) waste material namely Rice Husk Ash (RHA) to replace the Ordinary Portland Cement (OPC) partially in grout, also, using Polymer Modified Bitumen (PMB) to develop Open-Graded Asphalt (OGA) pavement without using cellulous fibre. The study focused on assessment of mechanical properties of the obtained SFP mixes with and without PMB. The results of study showed that using of PMB increased the Marshall Stability up to 100% and indirect tensile strength up to 50%. The Marshall Retained Stability gave about 90% which is quite higher the minimum required limit (70%). The results also revealed that RHA can be used as replacement for the OPC in SFP mixes. All investigated percentages showed satisfactory mechanical properties

    Evaluation for the effect of pavement type on the total life cost and environmental aspects of roads

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    There are several types of pavements which have been constructed around the world; flexible and rigid pavement. These pavements have major differences in terms of materials and construction process, giving the differences in their compositions and production process, each one of these pavements has some strength and weak points. The current study presents detailed comparison between these two pavements from the perspectives of the total life cost and environmental aspects using software Athena pavement Life Cycle Assessment (LCA). The assessment using LCA software is based on the construction materials, the construction and maintenance process as well as the machines and vehicles used during the construction, and the life cycle of pavement. Two majors streets were selected for the purpose of the comparison, the first street is called the street of coaches station in Al-Diwaniyah city and the second street is Om Al-Kheil street. The street of coaches station was constructed with composite pavement layers (full rigid pavement layers covered by 5 cm flexible pavement layer). On the other hand, the street of Om Al-Kheil was constructed with full layers of flexible pavement. The results of Life Cycle Cost Analysis (LCCA) showed that initial construction cost of composite pavement is higher than that of flexible pavement by 31%, while the total maintenance cost for flexible pavement is about 24 % more than of composite pavement. The diesel oil and gasoline had consumed by higher quantities during the preparation and construction stages of flexible pavement compared with composite pavement. Therefore, the environmental impact and gases emissions is more consumed during the construction of flexible pavement

    Psychological Problems among Different Hereditary Blood Disease in Basrah, A Cross Sectional Study

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    Hereditary blood disease are so common inherited problems in the world and in Iraq ,as far as the life span of the patients did increased psychosocial problems are greatly expected to increased and were studied through a different series through out the world ,the problem was understudied on the national prospect that nictitate a study to highlight the issue methodes:104 different diagnoses hereditary blood disease patient were enrolled in this cross sectional study that depend on direct interview and fill of 2 revised questionnaire that covered psycological,social and educational impact of the disease in a period of 6 months in Basra center for hereditary blood disease results: More than 50.96 % showed agreement toward being hopeless because of the illness,58.65 % agree for being nervous and upset ,59.62% for feels depressed and sad ,50% feel anxious for their future and 50.92% feel nervous because of the illness) Existence of psychological problems among the patients studied did concluded and issuing screening for the problems among the patients and establishing psychological help programs did recommended

    Investigation of Groundwater and The Impact of Over-Pumping in Al-Haydariyah Region, Iraq

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    In this study; a three-dimensional model was created to simulate groundwater in Al-Haydariyah area of the governorate of Al-Najaf. A solid model was created to utilize the cross sections of 25 boreholes in the research region, and it was made out of two layers: sand and clay. The steady-state calibration was employed in six observation wells to calibrate the model and establish the hydraulic conductivity, which was 17.49 m/d for sand and 1.042 m/d for clay, with a recharge rate of 0.00007 m/day. The wells in the research region were reallocated with a distance of 1500 m between each well, resulting in 140 wells evenly distributed throughout the study area and with a discharge of 5 l/s, and the scenarios were run for 1000 days to explore the impact of over-pumping on groundwater levels. The wells were operated at three different operating hours: 4, 8, and 12 h/d. According to the results, the largest water table decrease for each scenario was 0.35, 8.25, and 8.68 m, respectively. It was discovered that the first scenario, with an operating duration of 4 h/day and a discharge of 72 l/s, was the best scenario in which dry cells did not happen

    Production of Hard Grade Bitumen for Using in High Modulus Asphalt Concrete

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    قد تتعرض الخرسانة الاسفلتية الاعتيادية لعدة اضرار مثل شقوق الكلل والتخدد وتتفاقم درجة هذه الاضرار مع الظروف المناخية القاسية والحمل المروري المتكرر. يمكن اعتبار الخلطة الاسفلتية العالية المرونة المصممة وفقا للطريقة الفرنسية (EME)) أحد الحلول المهمة للحد من هذه الاضرار. ان انتاج هذا النوع من الخليط يتطلب اسفلت (كمادة رابطة) عالي الصلابة. البحث الحالي يتضمن طريقة جديدة لأنتاج الاسفلت بتدرج اختراق نوع hard)) ليلائم متطلبات الاسفلت العالي الصلابة المستخدم لأنتاج الخلطة الاسفلتية العالية المرونة المصممة وفقا للطريقة الفرنسية. العمل المختبري يتضمن خلط البوليمر ومصلبه مع الاسفلت الاعتيادي لأنتاج الاسفلت الجديد العالي الصلابة. نظرا لأن شقوق الكلل هي أكثر المخاوف المتعلقة بالأسفلت (كمادة رابطة) العالي الصلابة والخلطة الاسفلتية العالية المرونة، لذلك تمت إضافة حبيبات المطاط الى الاسفلت المنتج العالي الصلابة لتحسين أداء التبليط في مقاومة شقوق الكلل. تم اجراء اختباري مطياف الاشعة تحت الحمراء ومسح المجهر الالكتروني للأسفلت الاعتيادي وللأسفلت العالي الصلابة. كانت القيمة المثلى المختارة للمضافات لانتاج الاسفلت العالي الصلابة المستخدم في الخلطة الاسفلتية العالية المرونة هي 4% و0.4% من وزن الاسفلت للنوفولاك والهكسامين على التوالي، بينما نسبة حبيبات المطاط لتحسين المرونة هي 0.5%. أظهرت نتائج الاختبارات المجهرية والاشعة تحت الحمراء للاسفلت المنتج حدوث تداخلا ميكانيكيا بين الاسفلت والمضافات أدى الى تحسن كبير في الخواص الميكانيكة للاسفلت المنتج. الاسفلت المنتج قد حقق متطلبات الاسفلت العالي الصلابة وبالتالي يمكن استخدامه في انتاج الخلطة الاسفلتية العالية المرونة المصممة وفق الطريقة الفرنسية.The conventional Hot Mix Asphalt (HMA) may suffer from several distress such as fatigue cracks and rutting. These distresses increase with severe climate conditions and reputation of traffic load. The High Modulus Asphalt Concrete (HMAC) designed according to the French method (EME) can be considered as one of the important solutions for these distresses. The production of HMAC requires hard grade bitumen. The current research involved a novel way to produce hard grade bitumen (asphalt binder) to be consonant with the requirements of hard grade bitumen used for a HMAC. The experimental work involved mixing polymer and cross-linking agent with conventional bitumen to get the new bitumen. Since the most concern with hard grade bitumen and HMAC is the fatigue cracks, Crumb Rubber (CR) was added to the obtained bitumen to improve the fatigue performance of the pavement. Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electronic Microscope (SEM) tests were carried out on the conventional and hard grade bitumen. The optimal value of additives was selected to meet the requirement of hard grade bitumen was 4% Novolac from weight of bitumen and 10 % of Hexamine from weight of Novolac (i.e. 0.4% of weight of bitumen), while the selected CR ratio to improve flexibility was 0.5% from weight of bitumen. FTIR and SEM test results showed that a mechanical interaction was occurring between the bitumen and the additives leads to greatly improve the mechanical properties of resulting bitumen. The obtained bitumen is satisfied to required standards and can be used for HMAC according to French method
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